Expansible and contractible element and mounting therefor



Oct. 16, 1928. 1,687,842

I l. E. M cABE EXPANSIBLE AND CONTRACTIBLE ELEMENT AND MOUNTING THEREFOR Filed Oct. 24, 1927 2 Sheets-Sheet 1 INVEN TOR. IRA E. M? CABE sy a l Fla 1L ATTORNEYS Oct. 16, 1928.

1,687,842 I. E.- MCCABE EXPANSIBLE AND CONTRACIIBLE ELEMENT AND MOUNTING THEREFOR Filed Oct. 24, 1927 2 Sheets-Sheet 2 /8/ INVENTOR.

IRA E. M9 9455 FIG. 17. I y -m.

A TTORNEYS;

Patented Oct. 16, 1928.

UNITED STATES IRA E. MOOAIBE, OF

cH IcAGo, rumors.

EXPANSIBIE AND CONTRACTIBLE ELEMENT AND MOUNTING- THEREFOR.

Application filed October 24, 1927. Serial No. 228,258.

This invention relates to improvements in Figure is a view similar to Figure 1,

expansible and contractible elements, such' illustrating a third type of end closure.

as are employed in thermostatic and pressure operated devices, and more particu- 5 larly to that type formed of thin resilient metal walls sealed about a space either filled with a gas or liquid, the volume of which varies in accordance with the temperature or'connected to a source of pressure, so that upon increase in temperature or pressure,

as the case may be, the opposite walls of the element expand or move away from each other and upon decrease in the same, the said walls contract or approach each other.

Elements of this general type are lmown in this art in various forms of Bourdon tubes, bellows and diaphragms. This invention contemplates a novel form and construction of diaphragm. The conventional g diaphragm is cylindrical in shape and comprises two circular plates of thin resilient material joined together about their peripheries. As the pressure between the circular plates varies, their centers move away from or approach each other, which movement is employed in various instruments for actuating various devices. The variations in the distances of movement of the centers of the circular plates or walls away from each other are necessarily limited when they are formed of metal because their peripheries are rigidly secured to each other or'to the adjacent walls of an interposed cylinder which can not depart from the circular 5 shape without permanent deformation of the metal walls which would defeat the purpose of the element.

For the purpose of more clearly describing this invention, reference is made to the accompanying drawings which illustrate a preferred form of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawings:

Figure 1 is a fragmentary view in longi tudinal vertical section of one end of the improved element illustrating one type of closure therefor.

Figure 2 is a sectional view of Figure 1 taken on the line 2-2.

Figure 3 is a view similar to Figure 1,

4 Figure 6 is a sectional view of Figure 5, takenon the line 66;

Figure 7 is a view in side elevation of this improved element under normal or contracted conditions, and Figures 8 and 9 are sectional views taken on the lines 8-8 and 9-9 respectively on Figure 7 F igure. 10 is a View in side elevation-of Figure 7 when the same is expanded and Figures 11, 12 and 13 are sectional Views taken on the lines 1111, 1212, and 13-13, respectively.

Figure 14.- is a top plan View of a mounting for this improved element to employ the movement thereof.

"Figure 15 is a view in end elevation of Figure 14.

Figure 16 is in side elevation of Figure 14, partly in section, illustrating the parts in normal position when the element is contracteda Figure 17 is a view similar to Figure 14, illustrating the position of the parts when the element is expanded.

While Bonrdon tubes have been formed from drawn tubes of resilient metal, they have always been given a curved or of]? center shape with one end closed and free with the other fixed and communicating to the source of pressure so that upon an increase in pres sure the tube tends .to become straight imparting a movement to the free end, which movement is employed for various purposes in various devices.- This invention contemplates forming a rectangular expansible and contractible element of the type described from a drawn tube of thin resilient metal flattened with its flat surfaces 1 and 2 parallel and as close to each other as possible and still allow the metal forming the side edges 3, to join the adjacent flat surfaces on a curve without crimping the body thereof. The opposite transverse cut edges 4. of the tube are joined and sealed. To obtain most eflicient operation of the element, it is preferable to form it with the curved edges of greater length than the cut and sealed edges, as will be hereinafter described.

The sealing of the transverse cut edges 4 of the tube may be accomplished in any desired manner, however, it is preferable in accomplishing the sealing to maintain the metal of the ends parallel and in the same plane with the flat sides 1 and 2. This can be done, as illustrated in Figures 1 and 2, 'byinserting a strip of flat metal 5 of the proper thickness with a portion extending beyond'each curved edge 3 and brazing, welding or otherwise securing to the walls or by employing a T shaped \strip 6, such as shown in Figures 3 and 4, or a channel sha ed closure 7 may be employed, as shown in igures-5, 6 and 7, into which the edges are expanded and secured. This latter type is preferable where the interior of the element is to be placed in communication with a source of pressure. In Figure 5 a small tube 8 is shown entering through-the channel closure 7 and sealed thereto by solder 9 upon the exterior thereof. In cases where the element is to be filled with a gas or liquid it may be inserted through the tube 8 which is thereafter crimped'and sealed adjacent the end closure, otherwise thetube 8 is connected at its free end to a source of pressure.

From Figures 7 to 13 it is seen that the integral curved edges 3 are of greater length than the sealed edges 4. As the normally flat parallel faces 1 and 2 are integral parts of the tube of thin resilient metal, are joined.

to each other by the integral curved edges 3 and thesealed transverse edges 4, when the internal pressure is increased by the expansion of the contained gas or liquid or by communicated pressure from the source, as the case may be, the op osite flat surfaces 1 and 2'are moved away from each other and, as they are a part of a tube, draw the curved integral edges 3 towards each other. The greatest amount of movement takes place where the diagonals of'the rectangle meet. The sealed edges 4 being rigid, the amount of curve imparted to the flat normally parallel faces decreases in both directions from the center to the sealed edges. The edges 3.being curved and an integral part of the resilient tube as well as being held rigid at each end of the sealed closure of the edges 4, upon an increase in internal pressure give on account of their resiliency and are caused to approach each other as the flat sides move away from eachother, and as their ends are held rigid this movement increases toward the center of each curved edge, whereby a greater amount of movement is accomplished at the center of the flat sides than if sides were rigidly held about their peripheries. While the sealed together they are carried upon the element so that as the center portion thereof swells under increased pressure, the sealed ends are drawn towards each other.

Upon an increase in pressure the element expands at its center and when the pressure 1s relieved, it returns to its normal shape on account of the nature of its material and constructlon. An exhaustion of pressure or the Figures 14 to 17, inclusive, illustrate a.

mounting of this improved element for employment in connection with a pressure operated device which comprises a flat base .plate 10 and spaced apart, cover 11 to contain the improved element 12 over which is mounted a follower plate 13 supporting the flanged base 14 of an operating shaft or pin 15 extending at right angles to the base and projecting through an opening provided therefor in the center of the cover 11. It is preferable to. support the top of the cover in such relation to the base plate as to allow normalexpansion and contraction to impart such movement of the center of the element to the operating pin and upon excessive expansion to be engaged thereby to reinforce the walls of the element to prevent a dangerous abnormal expansion.

1 Figures 15, 16 and 17 show the base 10 attached to the solid end 16 on the end of a stem 17 having a base'18 adapted to be placed in communication with a source of pressure which in turn is placed in communication with the interior of the element by the tube 8, heretofore described. The same mounting may be applied in a thermostatic device by sealing the tube 8 after the element has been filled with the desired gas or liquid and loeating the base 10 of the mounting in proper relations. In both cases the operating mech anism of the device in which the element is employed is arranged to be actuated by the movement of the operating pin 15.

What I claim is:

I 1. An expansible and contractible element comprising a section of flattened resilient metallic tubing with the ends thereof 'closed'and sealed.

2. An expansible and contractible element comprising a section resilient metallic tubing having opposite sides flattened and parallel'with each other and the ends thereof sealed with the edges of said flattened sides rigidly held parallel-to each other. ends 4 hold their respective ends rigidly 3. An expansible and 'contractible element comprising a section of flattened resilient metallic tlrbing of greater tubular length'than the flattened width and means for sealing the ends thereof with the edges of the flattened surfaces held in spaced apart relations by said seals.

4. An expansible 'a'nd' contractible ele-,

ment of thin resilient metal having oppositely disposed parallel sides integrally united by the metal thereof along two opposite edges and other edges sealed.

5. An expansible and contractible element of thin resilient metal having spaced apart parallel sides with two oppositely disposed curved integral edges and means engaging the free edges for maintaining them in their parallel relation and forming a seal at each respective end.

6. An expansible and contractible ele ment formed of a section of flattened resilient metallic tubing with the ends thereof closed and sealed mounted in a casing having spaced apart walls arranged to allow normal expansion of the element and be engaged thereby upon abnormal expansion to reinforce the flattened sides thereof.

7. An expansible and contractible element formed of a section of resilient metallic tubing having opposite sides flattened and parallel with the ends thereof closed and sealed mounted in a casing having opposite walls spaced apart to allow normal expansion of said element and be enga ed thereby to prevent abnormal expansion t ereof, and a plate arranged between one side of the element and the adjacent casing wall having an operating pin mounted thereon projecting through an aperture provided therefor at the center of said casing wall.

8. An expansible and contractible element formed of a section of resilient tubing having opposite sides flattened and parallel with the ends thereof closed and sealed mounted in a casing having opposite walls spaced apart to resist abnormal expansion of the element, a follower plate mounted within the casing upon one of the flattened sides of the element and coextending therewith, and a plate interposed between said follower and the adjacent casing wall having.

an operating pin mounted thereon projecting through an aperture provided therefor at the center of said adjacent casing wall.

IRA E. MoCABE. 

